Skip to main content Skip to navigation

Events in Physics

Show all calendar items

Ben Chapman (CFSA, Warwick): 'Ion Cyclotron Emission as a Diagnostic of the Time Evolution of Edge Density During ELM Crashes in KSTAR Plasmas'

- Export as iCalendar
Location: PS128

Abstract: Spectrally structured ion cyclotron emission (ICE) is detected alongside ELMs in KSTAR deuterium plasmas. For KSTAR ICE where the separation of spectral peak frequencies is close to the proton cyclotron frequency at the outer plasma edge, orbit calculations suggest that the driver may be a subset of centrally-born fusion protons on passing orbits. We report 1D3V PIC code modelling of this scenario for KSTAR ICE. We simulate the self-consistent nonlinear full orbit dynamics of energetic and thermal ions and electrons, in combination with the electric and magnetic fields. Multiple simulation runs enable us to infer the theoretical dependence of ICE spectral structure on bulk plasma parameters, notably density. It is observed on KSTAR that the cyclotron harmonic structure of the ICE spectrum usually chirps down, on sub-microsecond timescales, during an ELM crash; upward chirping is observed in a few cases. By matching these observations to the dependence of ICE on local density that we infer from our PIC simulations, we obtain submicrosecond resolution of the evolving edge density during the ELM crash. The downward ICE chirps reflect the density collapse during the crash, while the rare upward chirps may be due to locally rising edge density associated with ELM filaments.

Tags: CFSA Seminar

Show all calendar items

Academic Leave Diary

Click here


Physics Days

Event listing

Research Group Events




Particle Physics



Condensed Matter Physics


Open Funder Deadlines

UKRI - Daphne Jackson Fellowship

Diamond Studentships 2024


UKRI Deadlines

Due to the implementation of a new UKRI funding system (TFS) there will be a fixed quarterly deadlines for some grants which would previously have been on open calls, this is to allow necessary system amendments and updates.

The first deadline after implementation will be 28th September 2023 and applies to those calls listed below:

EPSRC New Investigator Award

EPSRC Network Grant

EPSRC Post Doctoral Fellowship

EPSRC Open Fellowship

EPSRC Open Plus Fellowship

EPSRC Working with overseas scientists

EPSRC Standard research grant

EPSRC Discipline hopping in ICT

EPSRC Overseas travel grant